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Kinahan PE, Townsend DW, Beyer T, Sashin D. Attenuation correction for a combined 3D PET/CT scanner. Med Phys 1998; 25:2046-53. [PMID: 9800714 DOI: 10.1118/1.598392] [Citation(s) in RCA: 502] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In this work we demonstrate the proof of principle of CT-based attenuation correction of 3D positron emission tomography (PET) data by using scans of bone and soft tissue equivalent phantoms and scans of humans. This method of attenuation correction is intended for use in a single scanner that combines volume-imaging (3D) PET with x-ray computed tomography (CT) for the purpose of providing accurately registered anatomical localization of structures seen in the PET image. The goal of this work is to determine if we can perform attenuation correction of the PET emission data using accurately aligned CT attenuation information. We discuss possible methods of calculating the PET attenuation map at 511 keV based on CT transmission information acquired from 40 keV through 140 keV. Data were acquired on separate CT and PET scanners and were aligned using standard image registration procedures. Results are presented on three of the attenuation calculation methods: segmentation, scaling, and our proposed hybrid segmentation/scaling method. The results are compared with those using the standard 3D PET attenuation correction method as a gold standard. We demonstrate the efficacy of our proposed hybrid method for converting the CT attenuation map from an effective CT photon energy of 70 keV to the PET photon energy of 511 keV. We conclude that using CT information is a feasible way to obtain attenuation correction factors for 3D PET.
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Comparative Study |
27 |
502 |
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Beyer T, Day GM, Price SL. The prediction, morphology, and mechanical properties of the polymorphs of paracetamol. J Am Chem Soc 2001; 123:5086-94. [PMID: 11457339 DOI: 10.1021/ja0102787] [Citation(s) in RCA: 225] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The analgesic drug paracetamol (acetaminophen) has two reported metastable polymorphs, one with better tableting properties than the stable form, and another which remains uncharacterized. We have therefore performed a systematic crystal structure prediction search for minima in the lattice energy of crystalline paracetamol. The stable monoclinic form is found as the global lattice-energy minimum, but there are at least a dozen energetically feasible structures found, including the well-characterized metastable orthorhombic phase. Hence, we require additional criteria to reduce the number of hypothetical crystal structures that can be considered as potential polymorphs. For this purpose the elastic properties and vapor growth morphology of the known and predicted structures have been estimated using second-derivative analysis and the attachment-energy model. These inexpensive calculations give reasonable agreement with the available experimental data for the known polymorphs. Some of the hypothetical structures are predicted to have a low growth rate and plate-like morphology, and so are unlikely to be observed. Another is only marginally mechanically stable. Thus, this first consideration of such properties in a crystal-structure prediction study appears to reduce the number of predicted polymorphs while leaving a few candidates for the uncharacterized form.
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Hetzel J, Eberhardt R, Herth FJF, Petermann C, Reichle G, Freitag L, Dobbertin I, Franke KJ, Stanzel F, Beyer T, Möller P, Fritz P, Ott G, Schnabel PA, Kastendieck H, Lang W, Morresi-Hauf AT, Szyrach MN, Muche R, Shah PL, Babiak A, Hetzel M. Cryobiopsy increases the diagnostic yield of endobronchial biopsy: a multicentre trial. Eur Respir J 2011; 39:685-90. [PMID: 21852332 DOI: 10.1183/09031936.00033011] [Citation(s) in RCA: 176] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Forceps, brushes or needles are currently the standard tools used during flexible bronchoscopy when diagnosing endobronchial malignancies. The new biopsy technique of cryobiopsy appears to provide better diagnostic samples. The aim of this study was to evaluate cryobiopsy over conventional endobronchial sampling. A total of 600 patients in eight centres with suspected endobronchial tumours were included in a prospective, randomised, single-blinded multicentre study. Patients were randomised to either sampling using forceps or the cryoprobe. After obtaining biopsy samples, a blinded histological evaluation was performed. According to the definitive clinical diagnosis, the diagnostic yield for malignancy was evaluated by a Chi-squared test. A total of 593 patients were randomised, of whom 563 had a final diagnosis of cancer. 281 patients were randomised to receive endobronchial biopsies using forceps and 282 had biopsies performed using a flexible cryoprobe. A definitive diagnosis was achieved in 85.1% of patients randomised to conventional forceps biopsy and 95.0% of patients who underwent cryobiopsy (p<0.001). Importantly, there was no difference in the incidence of significant bleeding. Endobronchial cryobiopsy is a safe technique with superior diagnostic yield in comparison with conventional forceps biopsy.
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Randomized Controlled Trial |
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176 |
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Freudenberg LS, Antoch G, Schütt P, Beyer T, Jentzen W, Müller SP, Görges R, Nowrousian MR, Bockisch A, Debatin JF. FDG-PET/CT in re-staging of patients with lymphoma. Eur J Nucl Med Mol Imaging 2003; 31:325-9. [PMID: 14647988 DOI: 10.1007/s00259-003-1375-y] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2003] [Accepted: 10/02/2003] [Indexed: 12/31/2022]
Abstract
The aim of this study was to evaluate the clinical significance of combined fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) in patients with lymphoma, and to compare the FDG-PET/CT staging results with those of FDG-PET and CT alone. Twenty-seven patients were studied. Each patient had clinical follow-up for >12 months and entered complete follow-up evaluation. Patient-based evaluation showed a sensitivity of 78% for CT alone, 86% for FDG-PET alone, 93% for CT and FDG-PET read side by side, and 93% for combined FDG-PET/CT imaging. Region-based evaluation showed a sensitivity for regional lymph node involvement of 61%, 78%, 91% and 96% respectively. FDG-PET/CT imaging is superior to CT alone ( P=0.02) and has additional benefit over FDG-PET alone due to exact anatomical localisation. We conclude that FDG-PET/CT imaging is accurate in re-staging lymphoma and offers advantages over separate FDG-PET and CT imaging.
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Clinical Trial |
22 |
171 |
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Rosenqvist M, Beyer T, Block M, den Dulk K, Minten J, Lindemans F. Adverse events with transvenous implantable cardioverter-defibrillators: a prospective multicenter study. European 7219 Jewel ICD investigators. Circulation 1998; 98:663-70. [PMID: 9715859 DOI: 10.1161/01.cir.98.7.663] [Citation(s) in RCA: 150] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND A newly developed classification system relates adverse events to the surgical procedure or the function of the implantable defibrillator. METHODS AND RESULTS Adverse events were monitored during prospective clinical evaluation of the Medtronic model 7219 Jewel ICD and were classified according to the definitions of the ISO 14155 standard for device clinical trials into 3 groups: severe and mild device-related and severe non-device-related adverse events. In addition, events were related to the surgical procedure, treatment with the device, or cardiac function. Seven hundred seventy-eight patients were followed up for an average of 4.0 months after ICD implantation. In total, 356 adverse events were observed in 259 patients. At 1, 3, and 12 months after ICD implantation, 99%, 98%, and 97% of the patients, respectively, survived; 95%, 93%, and 92%, respectively, were free of surgical reintervention; and 79%, 68%, and 51%, respectively, were free of any adverse event. Twenty patients died: 6 deaths were related to the surgical procedure, 12 deaths were considered unrelated to ICD treatment, and 2 patients died of an unknown cause. Of 111 nonlethal severe adverse device effects, 47 required surgical intervention, 19 times for correction of a dislodged lead. Inappropriate delivery of therapy was observed 128 times in 111 patients, and the events were typically resolved by reprogramming or drug adjustment. Nine of these required rehospitalization. CONCLUSIONS Approximately 50% of patients experience an adverse event within the first year after ICD implantation. The observed adverse event rate depends on the definitions and the prospective monitoring. The incidence of inappropriate therapy emphasizes the need for improved detection algorithms and for quality-of-life evaluations, especially when considering ICD treatment in high-risk but arrhythmia-free patients.
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Clinical Trial |
27 |
150 |
6
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Gaipl US, Kuenkele S, Voll RE, Beyer TD, Kolowos W, Heyder P, Kalden JR, Herrmann M. Complement binding is an early feature of necrotic and a rather late event during apoptotic cell death. Cell Death Differ 2001; 8:327-34. [PMID: 11550084 DOI: 10.1038/sj.cdd.4400826] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2000] [Revised: 11/21/2000] [Accepted: 12/05/2000] [Indexed: 11/08/2022] Open
Abstract
The phagocytosis of dying cells is an integral feature of apoptosis and necrosis. There are many receptors involved in recognition of dying cells, however, the molecular mechanisms of the scavenging process remain elusive. The activation by necrotic cells of complement is well established, however, the importance of complement in the scavenging process of apoptotic cells was just recently described. Here we report that the complement components C3 and C4 immediately bound to necrotic cells. The binding of complement was much higher for lymphocytes compared to granulocytes. In case of apoptotic cell death complement binding was a rather late event, which in lymphocytes was preceded by secondary necrosis. Taken together complement binding is an immediate early feature of necrosis and a rather late event during apoptotic cell death. We conclude that complement may serve as an opsonin for fragments of apoptotic cells that have escaped regular scavenging mechanisms.
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24 |
126 |
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Charron M, Beyer T, Bohnen NN, Kinahan PE, Dachille M, Jerin J, Nutt R, Meltzer CC, Villemagne V, Townsend DW. Image analysis in patients with cancer studied with a combined PET and CT scanner. Clin Nucl Med 2000; 25:905-10. [PMID: 11079589 DOI: 10.1097/00003072-200011000-00010] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare combined whole-body PET and CT images of different cancers with PET images alone. MATERIALS AND METHODS Thirty-two patients with known or possible cancers were examined using a combined positron emission tomographic (PET) and computed tomographic (CT) scanner. All data were acquired using this same combined scanner. After an injection of F-18 fluorodeoxyglucose (FDG), noncontrast helical CT imaging of the neck, chest, abdomen, or pelvis was performed. The spiral CT was followed by a PET scan covering the same axial extent as the CT. RESULTS Coregistered PET-CT images identified and localized 55 lesions. In 10 patients (31%), areas with variable amounts of normal physiologic FDG uptake were distinguished from potential uptake of FDG in a nearby neoplastic lesion. Improved localization was achieved in 9 patients (for a total of 13 lesions, or 24%). CONCLUSION Combined PET-CT images appear more effective than PET images alone to localize precisely neoplastic lesions and to distinguish normal variants from juxtaposed neoplastic lesions.
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25 |
94 |
8
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Papp L, Spielvogel CP, Grubmüller B, Grahovac M, Krajnc D, Ecsedi B, Sareshgi RAM, Mohamad D, Hamboeck M, Rausch I, Mitterhauser M, Wadsak W, Haug AR, Kenner L, Mazal P, Susani M, Hartenbach S, Baltzer P, Helbich TH, Kramer G, Shariat SF, Beyer T, Hartenbach M, Hacker M. Supervised machine learning enables non-invasive lesion characterization in primary prostate cancer with [ 68Ga]Ga-PSMA-11 PET/MRI. Eur J Nucl Med Mol Imaging 2021; 48:1795-1805. [PMID: 33341915 PMCID: PMC8113201 DOI: 10.1007/s00259-020-05140-y] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/29/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE Risk classification of primary prostate cancer in clinical routine is mainly based on prostate-specific antigen (PSA) levels, Gleason scores from biopsy samples, and tumor-nodes-metastasis (TNM) staging. This study aimed to investigate the diagnostic performance of positron emission tomography/magnetic resonance imaging (PET/MRI) in vivo models for predicting low-vs-high lesion risk (LH) as well as biochemical recurrence (BCR) and overall patient risk (OPR) with machine learning. METHODS Fifty-two patients who underwent multi-parametric dual-tracer [18F]FMC and [68Ga]Ga-PSMA-11 PET/MRI as well as radical prostatectomy between 2014 and 2015 were included as part of a single-center pilot to a randomized prospective trial (NCT02659527). Radiomics in combination with ensemble machine learning was applied including the [68Ga]Ga-PSMA-11 PET, the apparent diffusion coefficient, and the transverse relaxation time-weighted MRI scans of each patient to establish a low-vs-high risk lesion prediction model (MLH). Furthermore, MBCR and MOPR predictive model schemes were built by combining MLH, PSA, and clinical stage values of patients. Performance evaluation of the established models was performed with 1000-fold Monte Carlo (MC) cross-validation. Results were additionally compared to conventional [68Ga]Ga-PSMA-11 standardized uptake value (SUV) analyses. RESULTS The area under the receiver operator characteristic curve (AUC) of the MLH model (0.86) was higher than the AUC of the [68Ga]Ga-PSMA-11 SUVmax analysis (0.80). MC cross-validation revealed 89% and 91% accuracies with 0.90 and 0.94 AUCs for the MBCR and MOPR models respectively, while standard routine analysis based on PSA, biopsy Gleason score, and TNM staging resulted in 69% and 70% accuracies to predict BCR and OPR respectively. CONCLUSION Our results demonstrate the potential to enhance risk classification in primary prostate cancer patients built on PET/MRI radiomics and machine learning without biopsy sampling.
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Randomized Controlled Trial |
4 |
87 |
9
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Stach CM, Turnay X, Voll RE, Kern PM, Kolowos W, Beyer TD, Kalden JR, Herrmann M. Treatment with annexin V increases immunogenicity of apoptotic human T-cells in Balb/c mice. Cell Death Differ 2000; 7:911-5. [PMID: 11279536 DOI: 10.1038/sj.cdd.4400715] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Exposure of phosphatidylserine on the outer leaflet of the cytoplasmic membrane is an early event during apoptotic cell death and serves as a recognition signal for phagocytes. Usually the clearance of apoptotic cells does not initiate inflammation or immune response. We investigated the immune response in Balb/c mice towards apoptotic human T-cells. Animals injected with apoptotic cells showed significantly reduced humoral immune responses, especially Th1-dependent IgG2a titres, compared to controls immunised with viable cells. However, treatment of apoptotic cells with annexin V (AxV) significantly increased the humoral immune response. AxV binds with high affinity to anionic phospholipids and as a result interferes with the phosphatidylserine recognition by phagocytes. Our results indicate that AxV treatment may be used to increase the efficiency of apoptotic cell-based vaccines, e.g. some tumour vaccines.
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25 |
67 |
10
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Abraham CR, Werter CR, Ata A, Hazimeh YM, Shah US, Bhakta A, Tafen M, Singh PT, Beyer TD, Stain SC. Predictors of Hospital Readmission after Bariatric Surgery. J Am Coll Surg 2015; 221:220-7. [PMID: 26047761 DOI: 10.1016/j.jamcollsurg.2015.02.018] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Identification of factors that might predict readmission after bariatric surgery could help surgeons target high-risk patients. The purpose of this study was to identify comorbidities, surgical variables, and postoperative complications associated with readmission. STUDY DESIGN Patients with bariatric surgery as their primary procedure were identified from the 2012 American College of Surgeons (ACS) NSQIP database. Patient variables, operative times, and major postoperative complications were analyzed for predictors of readmission. The ACS NSQIP estimated probability of morbidity (MORBPROB) was also considered. Chi-square tests and Poisson regression were used for statistical analysis to identify significant predictors. RESULTS There were 18,186 patients who met inclusion criteria. There were 1,819 who had a laparoscopic gastric band, 9,613 who had laparoscopic Roux-en-Y gastric bypass (RYGB), 6,439 who had gastroplasties (vertical banded gastroplasty and sleeve), and 315 who had open RYGB. Age, sex, BMI, American Society of Anesthesiologists (ASA) class, diabetes, hypertension, steroid use, type of procedure, and operative time all were significantly associated with readmission within 30 days of operation. All major postoperative complications were significant predictors of readmission. Patients expected to be at high risk based on the ACS NSQIP MORBPROB had a significantly higher rate of readmissions. The overall readmission rate for patients undergoing bariatric surgery was 5%. The readmission rate among patients with any major complication was 31%. CONCLUSIONS Bariatric surgery is a low-risk procedure. Complexity of operation, ASA class, prolonged operative time, and major postoperative complications are important determinants of high risk for readmission. The ACS NSQIP MORBPROB may be a useful tool to identify and target patients at risk for readmission.
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Journal Article |
10 |
66 |
11
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Schmitt C, Brachmann J, Karch M, Waldecker B, Navarrete L, Montero M, Beyer T, Kübler W. Reverse use-dependent effects of sotalol demonstrated by recording monophasic action potentials of the right ventricle. Am J Cardiol 1991; 68:1183-7. [PMID: 1951078 DOI: 10.1016/0002-9149(91)90191-m] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In 22 patients referred for electrophysiologic study, monophasic action potentials (MAP) were recorded from the right ventricular aspect of the ventricular septum. The duration of MAP at 90% (MAP90) and 30% (MAP30) repolarization was measured in sinus rhythm, at a constant atrial paced cycle length of 600 ms for 3 minutes and at constant ventricular paced cycle lengths of 600, 500, 400 and 300 ms for 20 beats. Programmed ventricular stimulation from the apex of the right ventricle was performed at a basic drive cycle length of 400 ms and MAP90 and MAP30 of premature beats was determined. Changes of MAP duration were assessed 20 minutes after administration of intravenous sotalol 1.5 mg/kg. Sotalol significantly increased MAP90 and MAP30 in sinus rhythm. This was independent from sinus cycle length prolongation as evidenced by a significant prolongation of MAP90 and MAP30 with constant atrial pacing after sotalol. With slow ventricular stimulation frequencies and with long coupling intervals at programmed ventricular stimulation, sotalol significantly prolonged MAP90 and MAP30; with high stimulation frequencies and at short coupling intervals the action potential-prolonging effect of sotalol was diminished, indicating a reverse use-dependent effect of sotalol on repolarization of the right ventricle in humans.
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53 |
12
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Veit P, Kühle C, Beyer T, Kuehl H, Herborn CU, Börsch G, Stergar H, Barkhausen J, Bockisch A, Antoch G. Whole body positron emission tomography/computed tomography (PET/CT) tumour staging with integrated PET/CT colonography: technical feasibility and first experiences in patients with colorectal cancer. Gut 2006; 55:68-73. [PMID: 15970580 PMCID: PMC1856388 DOI: 10.1136/gut.2005.064170] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AIM The aim of this study was to implement an imaging protocol for positron emission tomography/computed tomography (PET/CT) colonography and to combine this protocol with whole body PET/CT tumour staging for a single whole body examination for routine clinical use. SUBJECTS AND METHODS A whole body PET/CT protocol for tumour staging and a protocol for PET/CT colonography were integrated into one examination. Fourteen prospective patients with suspected colorectal cancer underwent whole body PET/CT after aqueous bowel distension and pharmacological bowel relaxation. Colonoscopy and histopathology served as the standards of reference in all patients. RESULTS The modified PET/CT examination detected all but one lesion in the colon. One additional lesion was detected in a patient with incomplete colonoscopy due to high grade luminal stenosis. One polyp with malignant conversion was identified with the modified PET/CT protocol. PET/CT colonography proved accurate in local lymph node staging and staged nine out of 11 patients correctly. Six additional extracolonic tumour sites were detected based on the whole body staging approach. CONCLUSION Whole body PET/CT with integrated colonography is technically feasible for whole body staging in patients with colorectal cancer. Based on these initial diagnostic experiences, this integrated protocol may be of substantial benefit in staging patients with colorectal cancer, focusing on patients with incomplete colonoscopy and those with small synchronous bowel lesions.
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research-article |
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Schmitt C, Brachmann J, Waldecker B, Navarrete L, Beyer T, Pfeifer A, Kübler W. Implantable cardioverter defibrillator: possible hazards of electromagnetic interference. Pacing Clin Electrophysiol 1991; 14:982-4. [PMID: 1715073 DOI: 10.1111/j.1540-8159.1991.tb04145.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We report on three patients with an automatic, implantable cardioverter defibrillator (AICD, CPI) in whom the device had been deactivated due to electromagnetic interference. In all cases, the source of the electromagnetic disturbances could be identified.
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Case Reports |
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Bailey DL, Pichler BJ, Gückel B, Barthel H, Beer AJ, Bremerich J, Czernin J, Drzezga A, Franzius C, Goh V, Hartenbach M, Iida H, Kjaer A, la Fougère C, Ladefoged CN, Law I, Nikolaou K, Quick HH, Sabri O, Schäfer J, Schäfers M, Wehrl HF, Beyer T. Combined PET/MRI: Multi-modality Multi-parametric Imaging Is Here: Summary Report of the 4th International Workshop on PET/MR Imaging; February 23-27, 2015, Tübingen, Germany. Mol Imaging Biol 2015; 17:595-608. [PMID: 26286794 DOI: 10.1007/s11307-015-0886-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This paper summarises key themes and discussions from the 4th international workshop dedicated to the advancement of the technical, scientific and clinical applications of combined positron emission tomography (PET)/magnetic resonance imaging (MRI) systems that was held in Tübingen, Germany, from February 23 to 27, 2015. Specifically, we summarise the three days of invited presentations from active researchers in this and associated fields augmented by round table discussions and dialogue boards with specific topics. These include the use of PET/MRI in cardiovascular disease, paediatrics, oncology, neurology and multi-parametric imaging, the latter of which was suggested as a key promoting factor for the wider adoption of integrated PET/MRI. Discussions throughout the workshop and a poll taken on the final day demonstrated that attendees felt more strongly that PET/MRI has further advanced in both technical versatility and acceptance by clinical and research-driven users from the status quo of last year. Still, with only minimal evidence of progress made in exploiting the true complementary nature of the PET and MRI-based information, PET/MRI is still yet to achieve its potential. In that regard, the conclusion of last year's meeting "the real work has just started" still holds true.
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Review |
10 |
46 |
15
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Thorwarth D, Beyer T, Boellaard R, de Ruysscher D, Grgic A, Lee JA, Pietrzyk U, Sattler B, Schaefer A, van Elmpt W, Vogel W, Oyen WJG, Nestle U. Integration of FDG-PET/CT into external beam radiation therapy planning: technical aspects and recommendations on methodological approaches. Nuklearmedizin 2012; 51:140-53. [PMID: 22473130 DOI: 10.3413/nukmed-0455-11-12] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 03/19/2012] [Indexed: 12/20/2022]
Abstract
UNLABELLED This work addresses the clinical adoption of FDG-PET/CT for image-guided radiation therapy planning (RTP). As such, important technical and methodological aspects of PET/CT-based RTP are reviewed and practical recommendations are given for routine patient management and clinical studies. First, recent developments in PET/CT hardware that are relevant to RTP are reviewed in the context of quality control and system calibration procedures that are mandatory for a reproducible adoption of PET/CT in RTP. Second, recommendations are provided on image acquisition and reconstruction to support the standardization of imaging protocols. A major prerequisite for routine RTP is a complete and secure data transfer to the actual planning system. Third, state-of-the-art tools for image fusion and co-registration are discussed briefly in the context of PET/CT imaging pre- and post-RTP. This includes a brief review of state-of-the-art image contouring algorithms relevant to PET/CT-guided RTP. Finally, practical aspects of clinical workflow and patient management, such as patient setup and requirements for staff training are emphasized. PET/CT-guided RTP mandates attention to logistical aspects, patient set-up and acquisition parameters as well as an in-depth appreciation of quality control and protocol standardization. CONCLUSION Upon fulfilling the requirements to perform PET/CT for RTP, a new dimension of molecular imaging can be added to traditional morphological imaging. As a consequence, PET/CT imaging will support improved RTP and better patient care. This document serves as a guidance on practical and clinically validated instructions that are deemed useful to the staff involved in PET/CT-guided RTP.
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Review |
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16
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Bailey DL, Pichler BJ, Gückel B, Barthel H, Beer AJ, Botnar R, Gillies R, Goh V, Gotthardt M, Hicks RJ, Lanzenberger R, la Fougere C, Lentschig M, Nekolla SG, Niederdraenk T, Nikolaou K, Nuyts J, Olego D, Riklund KÅ, Signore A, Schäfers M, Sossi V, Suminski M, Veit-Haibach P, Umutlu L, Wissmeyer M, Beyer T. Combined PET/MRI: from Status Quo to Status Go. Summary Report of the Fifth International Workshop on PET/MR Imaging; February 15-19, 2016; Tübingen, Germany. Mol Imaging Biol 2016; 18:637-50. [PMID: 27534971 PMCID: PMC5010606 DOI: 10.1007/s11307-016-0993-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This article provides a collaborative perspective of the discussions and conclusions from the fifth international workshop of combined positron emission tomorgraphy (PET)/magnetic resonance imaging (MRI) that was held in Tübingen, Germany, from February 15 to 19, 2016. Specifically, we summarise the second part of the workshop made up of invited presentations from active researchers in the field of PET/MRI and associated fields augmented by round table discussions and dialogue boards with specific topics. This year, this included practical advice as to possible approaches to moving PET/MRI into clinical routine, the use of PET/MRI in brain receptor imaging, in assessing cardiovascular diseases, cancer, infection, and inflammatory diseases. To address perceived challenges still remaining to innovatively integrate PET and MRI system technologies, a dedicated round table session brought together key representatives from industry and academia who were engaged with either the conceptualisation or early adoption of hybrid PET/MRI systems. Discussions during the workshop highlighted that emerging unique applications of PET/MRI such as the ability to provide multi-parametric quantitative and visual information which will enable not only overall disease detection but also disease characterisation would eventually be regarded as compelling arguments for the adoption of PET/MR. However, as indicated by previous workshops, evidence in favour of this observation is only growing slowly, mainly due to the ongoing inability to pool data cohorts from independent trials as well as different systems and sites. The participants emphasised that moving from status quo to status go entails the need to adopt standardised imaging procedures and the readiness to act together prospectively across multiple PET/MRI sites and vendors.
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Congress |
9 |
44 |
17
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Beyer TD, Solorzano CC, Prinz RA, Babu A, Nilubol N, Patel S. Oral vitamin D supplementation reduces the incidence of eucalcemic PTH elevation after surgery for primary hyperparathyroidism. Surgery 2007; 141:777-83. [PMID: 17560254 DOI: 10.1016/j.surg.2007.01.025] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2006] [Revised: 12/27/2006] [Accepted: 01/02/2007] [Indexed: 11/25/2022]
Abstract
BACKGROUND As many as 43% of patients will have normocalcemic intact parathyroid hormone (PTH) elevation after undergoing curative parathyroidectomy for primary hyperparathyroidism. This phenomenon may be due in part to an absolute or relative deficiency of vitamin D, which is under-recognized in patients with primary hyperparathyroidism. METHODS From September 1, 2004, to September 30, 2005, 86 consecutive patients underwent parathyroidectomy for primary sporadic hyperparathyroidism (psHPT). The patients were segregated into 2 groups based on postoperative management. Group 1 was composed of 26 patients who received routine oral calcitriol and calcium carbonate postoperatively. The 60 patients in the second group (group 2) received calcium carbonate postoperatively at the discretion of the primary surgeon. RESULTS A total of 85 patients (99%) achieved postoperative cure with sustained reduction in serum calcium. Within 30 days postoperatively, mean serum PTH levels normalized in both groups (41 +/- 31 vs 39 +/- 31 pg/ml; P = .91). However, at 1 to 3 months postoperatively, mean serum calcium levels remained similar (9.5 +/- 0.7 vs 9.3 +/- 0.5 mg/dl; P = .39) whereas mean serum PTH levels in groups 1 and 2 were 43 +/- 25 pg/ml and 67 +/- 45 pg/ml (P = .02), respectively. At 4 to 6 months postoperatively, mean PTH was again higher in group 2 (36 +/- 22 vs 67 +/- 35; P = .03), whereas mean serum calcium levels were normal (9.2 +/- 0.8 vs 9.6 +/- 0.4 mg/dl; P = .18). The incidence of postoperative normocalcemic PTH elevation was significantly higher in group 2 at 1 to 3 months (14% vs 39%; P = .04) and at 7 to 12 months (22% vs 83%; P = .04). CONCLUSIONS Vitamin D supplementation following parathyroidectomy for primary hyperparathyroidism reduces the incidence of postoperative eucalcemic PTH elevation.
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Veit-Haibach P, Antoch G, Beyer T, Stergar H, Schleucher R, Hauth EAM, Bockisch A. FDG-PET/CT in restaging of patients with recurrent breast cancer: possible impact on staging and therapy. Br J Radiol 2007; 80:508-15. [PMID: 17537758 DOI: 10.1259/bjr/17395663] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We aimed to compare the value of combined positron emission tomography (PET)/CT, PET+CT (viewed side by side), CT alone and PET alone concerning the rTNM stage and influence on therapy in patients with recurrent breast cancer. 44 patients with suspicion of recurrent breast cancer underwent whole-body [18F]-2-fluoro-2-deoxy-d-glucose (FDG)-PET/CT. Images of combined PET/CT, PET+CT, PET alone and CT alone were evaluated by four blinded reader teams. Diagnostic accuracies and influence on therapy were compared. Histology and a mean clinical follow up of 456 days served as the standard of reference. Differences between the staging procedures were tested for statistical significance by McNemar's test. Overall TNM tumour stage was correctly determined in 40/44 patients with PET/CT, in 38/44 with PET+CT, in 36/44 with PET alone and in 36/44 patients with CT alone. No statistically significant difference was detected between all tested imaging modalities. PET/CT changed the therapy in two patients compared with PET+CT, in four patients compared with PET alone and in five patients compared with CT alone. Combined PET/CT appeared to be more accurate in assessing the rTNM and showed a moderate impact on therapy over PET and CT. Minor improvements were noted when compared with PET+CT. Experienced readers might therefore be able to provide accurate staging results for further therapy from separately acquired studies.
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Bailey DL, Antoch G, Bartenstein P, Barthel H, Beer AJ, Bisdas S, Bluemke DA, Boellaard R, Claussen CD, Franzius C, Hacker M, Hricak H, la Fougère C, Gückel B, Nekolla SG, Pichler BJ, Purz S, Quick HH, Sabri O, Sattler B, Schäfer J, Schmidt H, van den Hoff J, Voss S, Weber W, Wehrl HF, Beyer T. Combined PET/MR: The Real Work Has Just Started. Summary Report of the Third International Workshop on PET/MR Imaging; February 17-21, 2014, Tübingen, Germany. Mol Imaging Biol 2016; 17:297-312. [PMID: 25672749 PMCID: PMC4422837 DOI: 10.1007/s11307-014-0818-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This paper summarises the proceedings and discussions at the third annual workshop held in Tübingen, Germany, dedicated to the advancement of the technical, scientific and clinical applications of combined PET/MRI systems in humans. Two days of basic scientific and technical instructions with "hands-on" tutorials were followed by 3 days of invited presentations from active researchers in this and associated fields augmented by round-table discussions and dialogue boards with specific themes. These included the use of PET/MRI in paediatric oncology and in adult neurology, oncology and cardiology, the development of multi-parametric analyses, and efforts to standardise PET/MRI examinations to allow pooling of data for evaluating the technology. A poll taken on the final day demonstrated that over 50 % of those present felt that while PET/MRI technology underwent an inevitable slump after its much-anticipated initial launch, it was now entering a period of slow, progressive development, with new key applications emerging. In particular, researchers are focusing on exploiting the complementary nature of the physiological (PET) and biochemical (MRI/MRS) data within the morphological framework (MRI) that these devices can provide. Much of the discussion was summed up on the final day when one speaker commented on the state of PET/MRI: "the real work has just started".
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Krause BJ, Beyer T, Bockisch A, Delbeke D, Kotzerke J, Minkov V, Reiser M, Willich N. [FDG-PET/CT in oncology. German Guideline]. Nuklearmedizin 2008; 46:291-301. [PMID: 18084685 DOI: 10.3413/nukmed-282] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
FDG-PET/CT examinations combine metabolic and morphologic imaging within an integrated procedure. Over the past decade PET/CT imaging has gained wide clinical acceptance in the field of oncology. This FDG-PET/CT guideline focuses on indications, data acquisition and processing as well as documentation of FDG-PET/CT examinations in oncologic patients within a clinical and social context specific to Germany. Background information and definitions are followed by examples of clinical and research applications of FDG-PET/CT. Furthermore, protocols for CT scanning (low dose and contrast-enhanced CT) and PET emission imaging are discussed. Documentation and reporting of examinations are specified. Image interpretation criteria and sources of errors are discussed. Quality control for FDG and PET/CT-systems, qualification requirements of personnel as well as legal aspects are presented.
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Galle J, Aust G, Schaller G, Beyer T, Drasdo D. Individual cell-based models of the spatial-temporal organization of multicellular systems--achievements and limitations. Cytometry A 2006; 69:704-10. [PMID: 16807896 DOI: 10.1002/cyto.a.20287] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Computational approaches of multicellular assemblies have reached a stage where they may contribute to unveil the processes that underlie the organization of tissues and multicellular aggregates. In this article, we briefly review and present some new results on a number of 3D lattice free individual cell-based mathematical models of epithelial cell populations. The models we consider here are parameterized by bio-physical and cell-biological quantities on the level of an individual cell. Eventually, they aim at predicting the dynamics of the biological processes on the tissue level. We focus on a number of systems, the growth of cell populations in vitro, and the spatial-temporal organization of regenerative tissues. For selected examples we compare different model approaches and show that the qualitative results are robust with respect to many model details. Hence, for the qualitative features and largely for the quantitative features many model details do not matter as long as characteristic biological features and mechanisms are correctly represented. For a quantitative prediction, the control of the bio-physical and cell-biological parameters on the molecular scale has to be known. At this point, slide-based cytometry may contribute. It permits to track the fate of cells and other tissue subunits in time and validated the organization processes predicted by the mathematical models.
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Beyer TD, Solorzano CC, Starr F, Nilubol N, Prinz RA. Parathyroidectomy outcomes according to operative approach. Am J Surg 2007; 193:368-72; discussion 372-3. [PMID: 17320537 DOI: 10.1016/j.amjsurg.2006.09.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Revised: 09/20/2006] [Accepted: 09/20/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND Parathyroidectomy for primary sporadic hyperparathyroidism (psHPT) has evolved with advances in preoperative gland localization and intraoperative parathyroid hormone (ioPTH) monitoring to minimally invasive approaches (MIPS). METHODS Two hundred twenty patients underwent parathyroidectomy for psHPT. Forty-nine patients underwent bilateral neck exploration (BNE) (group 1), 60 patients underwent BNE with ioPTH monitoring (group 2), and 111 patients underwent MIPS with ioPTH monitoring (group 3). RESULTS At 3 months postoperatively, mean serum calcium and intact parathyroid hormone (PTH) levels were similar between groups, and eucalcemia rates were 100%, 100%, and 99%. The ultimate rates of persistent disease and recurrence were also similar. Operative time was shorter in group 3 compared to group 2 (P < .001) but not group 1. Frozen sections and patient charges were significantly lower in group 3 compared to groups 1 and 2 (P < .005). CONCLUSION Parathyroidectomy for psHPT is highly successful with these techniques. When a MIPS approach can be done, it is potentially quicker and associated with lower patient charges.
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Choi LY, Torres R, Syed S, Boyle S, Ata A, Beyer TD, Rosati C. Sharps and Needlestick Injuries Among Medical Students, Surgical Residents, Faculty, and Operating Room Staff at a Single Academic Institution. JOURNAL OF SURGICAL EDUCATION 2017; 74:131-136. [PMID: 27397414 DOI: 10.1016/j.jsurg.2016.06.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 06/05/2016] [Accepted: 06/06/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND The hospital is a place of high risk for sharps and needlestick injuries (SNI) and such injuries are historically underreported. METHODS This institutional review board approved study compares the incidence of SNI among all surgical personnel at a single academic institution via an anonymous electronic survey distributed to medical students, surgical residents, general surgery attendings, surgical technicians, and operating room nurses. RESULTS The overall survey response rate was 37% (195/528). Among all respondents, 55% (107/195) had a history of a SNI in the workplace. The overall report rate following an initial SNI was 64%. Surgical staff reported SNIs more frequently, with an incidence rate ratio (IRR) of 1.33 (p = 0.085) when compared with attendings. When compared with surgical attendings, medical students (IRR of 2.86, p = 0.008) and residents (IRR of 2.21, p = 0.04) were more likely to cite fear as a reason for not reporting SNIs. Approximately 65% of respondents did not report their exposure either because of the time consuming process or the patient involved was perceived to be low-risk or both. CONCLUSIONS The 2 most common reasons for not reporting SNIs at our institution are because of the inability to complete the time consuming reporting process and fear of embarrassment or punitive response because of admitting an injury. Further research is necessary to mitigate these factors.
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Comparative Study |
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Edwards ME, Rotramel A, Beyer T, Gaffud MJ, Djuricin G, Loviscek K, Solorzano CC, Prinz RA. Improvement in the health-related quality-of-life symptoms of hyperparathyroidism is durable on long-term follow-up. Surgery 2006; 140:655-63; discussion 653-4. [PMID: 17011914 DOI: 10.1016/j.surg.2006.06.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Accepted: 06/04/2006] [Indexed: 11/16/2022]
Abstract
BACKGROUND Subjective symptoms such as decreased energy, chronic fatigue, and depression are associated with hyperparathyroidism. Studies have shown that these symptoms are improved during short-term follow-up after parathyroidectomy. This study evaluates the durability of this subjective improvement in quality-of-life symptoms in a large population of patients with follow-up greater than 1 year after operation. METHODS Between 2002 and 2005, 258 patients underwent parathyroidectomy, 100 (81 females and 19 males) of whom were available for this study. The patients were evaluated with a survey based on the Health Outcomes Institute Health Status Questionnaire. Some answers were quantified on a 1 to 6 scale, while others consisted of "yes" or "no" responses. Patients completed a questionnaire prior to parathyroidectomy and postoperatively at 1 month, 3 to 6 months, and 1 to 2 years or greater intervals. Statistical analysis was used to detect changes attributable to parathyroidectomy. A P value <.05 was considered statistically significant. RESULTS At 1-month follow-up, patients' perceptions of their overall health, energy level, and mood significantly improved. At 6-month follow-up, significant improvements in muscle strength, health, endurance, and relief of anxiety were documented. At the interval of 1 to 2 years, overall health, energy level, endurance, and relief of anxiety were improved. There was no significant decrement in the quality of life in these patients after parathyroidectomy. CONCLUSIONS Parathyroidectomy for hyperparathyroidism is associated with significant lasting improvement in subjective symptoms. The potential durable improvement in these quality-of-life symptoms is a valid indication for parathyroidectomy.
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Beyer T, Herrmann M, Reiser C, Bertling W, Hess J. Bacterial carriers and virus-like-particles as antigen delivery devices: role of dendritic cells in antigen presentation. CURRENT DRUG TARGETS. INFECTIOUS DISORDERS 2001; 1:287-302. [PMID: 12455402 DOI: 10.2174/1568005014605973] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Replicating attenuated strains of intracellular bacteria like Salmonella typhimurium, Listeria monocytogenes or Mycobacterium bovis Bacille Calmette Guérin (BCG), and non-replicating virus-like-particles (VLP) consisting, for instance, of the VP1-surface component of polyoma virus offer great potential as heterologous carriers delivering foreign protein antigens for immune recognition. Moreover, attenuated S. typhimurium and L. monocytogenes strains hold also great promise as delivery vehicles for DNA vaccines. Polyoma virus-specific VLP consisting of VP1-pentamers are also of interest as carrier devices for eukaryotic expression plasmids. At first sight these different replicating and non-replicating types of vehicles have little in common, but from an immunological point of view viable bacteria and non-viable VLP are both well suited for evoking protective immune responses via several routes of vaccine administration. As these antigen carriers generate humoral and cell-mediated immunity, the heterologous antigens are not only targeted to appropriate pathways of major histocompatibility (MHC) class I and class II antigen processing and presentation, but also generate an adequate cytokine milieu for promoting antigen-specific responses. The most prominent advantage of these carrier devices is presented by their capacity to directly target antigenic proteins or DNA vaccines to immature dendritic cells (DC) along their maturation pathway. Mature DC are the key antigen presenting cell population which efficiently mediates antigen transport to organised lymphoid tissues for the initiation of T cell responses. In general, uptake of these diverse antigen delivery systems by antigen presenting cells (APC) finally lead to efficacious immune responses in the control of pathogenic microorganisms and tumours.
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